The annual "Tribute in Light" memorial echoing the twin towers of the World Trade Center illuminates the night sky during the 10th Anniversary of the September 11, 2001 attacks at the World Trade Center, Sept. 11, 2011.

The number of people who have applied to the 9/11 Victims Compensation Fund for financial assistance has surged as the deadline looms this week, according to the nonprofit group 9/11 Health Watch.

As of June, a little over 17,000 people had applied to the fund, which was established as part of the 2010 James Zadroga 9/11 Health and Compensation Act to assist those who live and work near Ground Zero with medical expenses related to the terror attacks on the World trade Towers.

By last week the number had more than doubled to 36,000. The number is now approaching 40,000, according to the group's estimates.

Ben Chavet, the executive director of 9/11 Health Watch, said it's unclear how many people will ultimately sign up for the victims fund before the deadline. He said some estimates put the number of people who were in the vicinity of the towers on the day of the attacks at about 92,000 and it's unclear how many will become sick as a result.

"We don't really know if everyone who should come forward has come forward," he said. "And just because someone signs up for the fund doesn't mean they are eligible for compensation."

When the Thursday deadline passes, the fund will no longer accept registrants, even for those who have a covered illness.

This is particularly troubling because, as Dr. Michael Crane, an assistant professor of preventative medicine at Mount Sinai, pointed out, the studies looking at 9/11 illnesses have only reviewed cases up to about 2008.

"We don't even really think about most cancers until at least 10 years after a toxic event but we are already seeing an increase here that is at or approaching statistical significance. This is the first clue that cancers might be elevated in this population," Crane said.

An upcoming study by the New York City Police Department underscores this point. Conducted in conjunction with Cornell Weill Medical Center, the study found a fivefold increase in cancers among department members who spent time at the site of the World Trade Center terrorist attack. Incidence of one form of thyroid cancer showed a tenfold increase.

Eli Klienman, the NYPD's supervising chief surgeon said at a press conference yesterday that the preliminary study results were being released several months so that its members can have the information sooner than later.

Once you sign up for the fund, you have two years to complete the filing.

Arthur Schwartz, a principal at the law firm Advocates for Justice, called the claims process daunting. It involves an examination by a doctor affiliated with the World Trade Center Health Program, submission of detailed medical records and medical bills, employment records, and affidavits from various people who can vouch for your whereabouts on 9/11 and the following year, he said.

Claims processing can take up to two years and Schwartz worried that the increased number of claimants will slow the process down even more.

"With this greater number, I'm afraid people will be spending too many years waiting to get help. They need to find a way to speed things up," he said.

As of now, just 53 claim decisions have been made by the fund.

If you believe you are eligible for the compensation fund, you may find out more on how to file before the Thursday deadline by following this link. Chavet stressed that the fund remains open for claims filings despite the government shutdown.

Gail Robinson, director of public affairs for the New York Committee for Occupational Safety and Health said that while she definitely urged people to sign up for the victim's fund ahead of the deadline, free medical benefits will still be available to eligible victims, including screening, treatment and medicine for a number of cancers and other World Trade Center related conditions, including respiratory ailments, some mental health disorders and stomach problems such as GERD.

"Tens of thousands of people eligible for this have not signed up for the care they need and deserve, including responders and people who lived worked or attended school near the Trade Center site," she said.